Lecher wire system



LECHER WIRE SYSTEM Filed June 14, 1939 Patented Sept. 29, 1942 LECHEBWIRE SYSTEM Martin Vieweger, Berlin, Germany; vested in the.

Custodian Allen Property Application June 14, 1939, Serial No. 279,128In June 22, 1938 (Cl. ts-44) 7 Claims.

Inultra short wave apparatus it is not possible for. the oscillatorycircuits to be formed of so-called concentrated capacities andinductances, because the wave-lengths are too small to allow ofarranging a concentrated capacity or condenser. Also, in the case ofvery short wavelengths the self-capacities of the coils and theself-inductances of the condensers as well as of the leads thereto areparticulars that require consideration in certain respects. Therefore,the oscillatory circuits are formed as Lecher wire systems. that is tosay, systems comprising two wires which are parallel to each other. Thelength of such circuits is a multiple of M4, where A is the operativewavelength. Since the Lecher wire system has to be tuned it haspreviously been necessary to provide for varying the effective length01' the Lecher wires to effect the tuning.

According to the invention the Lecher wire system is not altered in thisway, thus being left constant in length. In a preferred embodiment ofthe invention the free ends of the Lecher wires are bent into a.semicircular shape and a disc or plate is arranged to be inserted intothe interspace of the wire ends so shaped. This disc, which to such endmay be rotatable or slidable, has a dielectric constant e greater thanthat of air, a fact which may be expressed by the relation 1. Thearrangement is such that the disc does not contact with the Lecherwires. The disc ma for instance, be of a ceramic material of the kind.having a high e-value and small losses, or may consist of polystyroleneor the like. By inserting between the Lecher wires a disc of this typethe timing may be varied to accord with frequencies lower than in thecase of Lecher wires not influenced by such a dielectric.

For variations relative to larger frequency ranges the inventionprovides a number of semicircular wire stages each comprisingsemicircular wiresandadiscadaptedtobeinsertedinto the interspace thereofto tune such stages in the aforesaid manner.

In the accompanying drawing, Fig. 1 is a diagrammatic viewshowing anelementary form of systems as provided by the invention, Fig. 2 is adiagrammatic representation illustrating a number of such ele entaryforms, these constituting stages adapted to be interconnected,

Fig. 3 is a di arammatic view showing a modiflcation of the arrangementrepresented in Fig. l.

L denotes Lecher wires which in Figs. 1 and 2 are shown to besemicircular at their free ends. A rotatable disc H is arranged to beturned into the interspace of these wire ends without contactingtherewith. In order to provide for interconnecting stages of the kindrepresented in Fig. l, switches S, Fig. 2, may be arranged to allow ofselectively elongating or shortening the wires L by either adding ordisconnecting emicircular divisions L. Each such division has a disc Hfor tuning it.

The constructional forms illustrated in Figs. 1 and 2 are susceptible ofmany variations. For instance, instead of the discs H wedge-shapedbodies may be shifted into the interspace of the free ends of the Lecherwires in a manner to continually increase the eil'ective e-value. Also,a plate as shown in Fig. 3 may be provided, which is composed of twoparts A, B each having an e-value diiierent from that of the other part.This plate, adapted to be moved indifferent directions as indicated bythe arrows, enables the effective e-value to be continually increased.

What is claimed is:

1. A Lecher wire system comprising a pair of Lecher wires and means foreilecting continuous tuning of said Lecher wires by varying the capacityper unit length of said wires from one end thereof comprising a bodyhaving a dielectric constant greater than unity mounted for selectiveadjustable insertion between said wires from one end thereof and alongthe length thereof, said member being in insulated relation with respectto said wires.

2. A system according to claim 1, in which the free ends of the Lecherwires are semicircular and in which the said body is a rotatable disc.

3. A system comprising a pair of Lecher wires,

pairs or conductors arrangedin line with these wires and adapted to beinterconnected serially therewith, switches'for selectivelyinterconnecting said Lecher wires and conductors. a body adapted to beinserted into the interspace of these Lecher wires, and other bodieseach allotted to one of the said pairs of conductors and adapted to beinserted into the interspaces of such conductors. the said bodies havinga dielectric constant greater than that of air.

4. A system according to claim 3, in which the said pairs of conductorsare semicircular.

5. A system according to claim 3. wherein the bodies allotted to saidpairs of conductors are rotatable discs.

6. A system according to claim 1, in which thesaidbodyisofaceramicmaterialhavingahigh dielectric constant and smalllosses.

7. A system according to claim 1, wherein the said body consists ofpolystyrolene. 1

MARTIN VIEWEGE'R.

